This invention relates to a refrigerator for storage of food products at low temperature, and more particularly to a temperature circuit for operation of a freezing chamber and a cold chamber thereof.
There are two basic types of conventional freezing refrigerators. The direct-cooling-type refrigerator uses an inner space of a box-like cooler for a freezing chamber with an evaporator positioned adjacent the walls thereof. The fan-type cooling refrigerator has a fan which circulates cold air to both the freezing chamber and the cold chamber. Such conventional refrigerators are described, for example, in Japanese Patent Disclosures Nos. 50-96963 and 50-148963. The two types each have advantages and disadvantages. In the direct-cooling-type refrigerator, food products on a bottom plate of the freezing chamber can be cooled rapidly. However, it takes a long time to cool food products stored above the bottom plate in the freezing chamber. In the fan-type cooling refrigerator, food products are more rapidly cooled in the regions off of the bottom plate of the freezer than those in contact with the bottom plate, as the latter products are often blocked from the circulating air currents. Accordingly, food products in both types of refrigerators are not cooled equivalently, and each type suffers from freezing cycle inefficiencies.